Consolidated Statements Of Cash Flows Consolidated Statements of Cash Flows Parenthetical (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011
Payments To Fund Decommissioning Fund	$ 2.3	$ 4.3

The cash outflow related to funding the decommissioning trust fund.

No definition available.

Name:	ee_PaymentsToFundDecommissioningFund
Namespace Prefix:	ee_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration